Elevation adjustment for sewing-machine feed



A. 0. SMITH.

ELEVATION ADJUSTMENT FOR SEWING MACHINE FEED. APPLICATION FILED jULY30, I918.

1,417,865, Patented May 30, 1922.

UNITED STATES PATENT OFFICE.

ALBERT 1). SMITH, OE DETROIT, MICHIGAN,

ELEVATION ADJUSTMENT FOE SE NING-MACHINE v Application filed July 30,

T 0 all whom may concern:

Be it known that I. ALBERT D. SMITH. a citizen of the United States, residing at Detroit, in the county of Wayne and State of Michigan, have invented certain new and useful Improvements in Elevation Adjustments for Sewing-Machine Feed, of which the following is a specification.

This invention pertains to feed mechanism for sewing machines, and has more particular reference to adjusting the elevation of the feed of a mechanism characterized by the inclusion of an oscillating rock shaft and a connection therefrom to the feed member for raising and lowering the latter, and a motion-train from the driving shaft for oscillating the rock shaft.

The primary object of the invention is to provide a simple and improved means for adjusting the degree of elevation. of a feed member of the character described, whereby a defective feed movement caused by wear of the joints and parts may be quickly and easily remedied by a simple adjustment, and also whereby the feed may be quickly adjusted to the correct elevation for various distinct classes of sewing, such. as for household and factory use and for fine and heavy materials.

Referring to the drawing,-

Figure 1 is an end elevation of a sewing machine equipped with the preferred embodiment of my improvement;

Fig. 2 is a full size plan sectional view taken on the line 22 of Fig. 1; and

Fig. 3'is a vertical sectional view on the line 3-3 of Fig. 2.

My present improvement relates particularly to means for varying the elevation of the feed member in a simple and effective manner. In the drawing, the feed member, indicated in general by reference character 5, is pivotally connected at its forward end to a crank arm 6, fixed to a feed-motion rock shaft 7 and is pivotally connected at its rear end through the agency of a translating link 8 and crank arm 9 to an elevation rock shaft 11. These rock shafts 7 and 11 are driven from the needle-bar driving shaft through the agency of separate lIlOillOIltrains, not shown in this case, which produce a four-motion feed movement. The means for operating the rock shaft may be of any suitable or preferred construction, such for example as described in my copending application, Serial No. 24:7, t27,

Specification of Letters Patent.

Patented May 30, 1922.

1918. Serial 1%. 247,426.

filed July 30, 1918. The mechanism shown in said application oscillates the crank arm 6 backwardly and forwardly to advance and retract the feed member and oscillates the crank arm 9 upwardly and downwardly to ralseand lower said member. In my copending application, means is provided for varying the length of the forward stroke and for reversing the direction of feed,-these variations being effected by changing the throw of the crank arm 6.

The crank arm 9, however, has a constant motion, and the purpose of the present invention is to provide a simple means, preferably arranged in the connection between this crank arm and the feed member. for relatively adjusting these parts to vary the elevation. It will be manifest that by varying the elevation of the feed member, the toothed or roughened portion 12 thereof will be projected more or less above the throat plate 13 during the feed movement so as to engage the work with the proper pressure. This relative adjustment is obtained by shortening or lengthening the distance between the pivots 14: and 15 at the upper andv lower ends of the link 8. The

pivotal relation between the feed member and. the link 8 at the upper end 14: remains constant. The pivot 15, however, is preferably in the form of a pivot bolt having a cylindricalshank 16 freely rotatable in the arm 9 and a reduced threaded end 17 passing throu h an elongated slot 18 in the link 8. A nut 19 on the threaded end 17 fixedly clamps the link 8 against the shoulder 21 on the pivotbolt. Thus, while the link 8 is fixed to the pivot bolt 15., the latter is free to oscillate in its connection with the crank arm 9.

It will be manifest that by loosening the nut 19 the link 8 may be vertically adjusted relatively to the crank arm 9 to vary the elevation of the feed member and that after the nut19 is tightened to secure the pivotal relation between the link 8 and the crank arm 9, these parts are still free to function in the usual way. "While they construction thus provided is exceeding simple, nevertheless, it accomplishes a very desired object and is thoroughly practical for the-purpose and is simple and easy to adjust.

I claim:

1. In a sewing machine feed mechanism, the combination of a feed member, a roc shaft having a crank arm, a pivot bolt in the end of said crank arm, a link pivotally connected at one end with the feed member and having an elongated opening through whichthe threaded end o'lsaid bolt passes, and a nut on said threaded end for fixedly securing the link to the pivot bolt,

which latter is freely pivotal on said crank arm. Q

2. In a sewing machine feed mechanism, the combination of an elevation rock-shaft, a feed-motion rock shaft, a feedtmember, a crank arm fixed to the feedmotion rockshaft and pivotally connected directly to pivoted in said crank arm, whereby the distance between the pivotal connections of said link may be varied for directly varying the elevation of the feedmember.

ALBERT 1). SMITH. 

